Author Topic: Plunger Chaincase screws  (Read 637 times)

Offline AdrianJ

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Plunger Chaincase screws
« on: 02.03. 2019 16:41 »
I've just bought a set of stainless Allen screws for the chaincase, but I've lost the piece of paper with my notes of which go where.
I appear to have two long, 7 medium and three short screws.
One of the long ones fits the extreme rear hole, but i am reluctant to wind the others in in case I do some damage.
Can anyone enlighten me about the screw positions please? The plunger case seems quite different to the SA.
I've searched the forum and found the lengths of the screws but not the positions.
Thanks in advance,
Adrian
'53 Plunger Flash, Steib S500.


Offline duTch

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Re: Plunger Chaincase screws
« Reply #1 on: 02.03. 2019 20:42 »

 Usually best to check while the cover is off, but if replacing the screws while in service, fairly much the three short ones go to front, medium ones behind those and the long ones rear and above or below the centre line . You should be able to gauge it with a bit of wire for a depth gauge.
  I didn't think all the ones in the set were long enough so customized my own anyway...
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
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Offline AdrianJ

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Re: Plunger Chaincase screws
« Reply #2 on: 02.03. 2019 22:51 »
Ta, That really helps, I'm not sure my new ones are all the right length. I'll use wire to make sure I don't destroy anything. I seem to have too many long screws, may have to shorten some.
Adrian
'53 Plunger Flash, Steib S500.


Online Swarfcut

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Re: Plunger Chaincase screws
« Reply #3 on: 02.03. 2019 23:26 »
Adrian...It is a good idea to make sure there is no crap and old jointing compound at the bottom of the blind holes. Smaller drill or a woodscrew, both hand held, will clean them out. As long as they do not bottom, it is a case of check and shorten to use the maximum  thread depth. The bolts should be 1/4 Whitworth Thread, same thread as sump plate studs or rocker cover studs, into the aluminium castings.

 Swarfy.

Offline AdrianJ

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Re: Plunger Chaincase screws
« Reply #4 on: 03.03. 2019 07:56 »
Thanks very much Swarfy.
Adrian
'53 Plunger Flash, Steib S500.


Online BSA_54A10

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Re: Plunger Chaincase screws
« Reply #5 on: 03.03. 2019 10:28 »
The bolts have different part numbers
The bolt lengths & threads are listed in the stainless fasteners BSA/Triumph fastener list
So parts book then list to check the screws.
Bike Beesa
Trevor

Offline AdrianJ

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Re: Plunger Chaincase screws
« Reply #6 on: 03.03. 2019 12:23 »
Hi Trevor,
I have the lengths sorted, it's just which go where that isn't clear (the parts book doesn't help with the positions) but I'll sort that with a piece of wire.
Adrian
'53 Plunger Flash, Steib S500.


Online Black Sheep

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Re: Plunger Chaincase screws
« Reply #7 on: 03.03. 2019 14:41 »
I run a 1/4" Whitworth tap down the holes. It's amazing how much crud can come out with the tap. Be careful not to over-tighten the cap screws - one reason I stick with the original cheese-headed screws.
2 twins, 2 singles, lots of sheep

Offline AdrianJ

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Re: Plunger Chaincase screws
« Reply #8 on: 03.03. 2019 17:40 »
Thanks very much everybody.
Sorted now, not too tight but hopefully oil tight.
Stacks of crud in the holes.
Adrian
'53 Plunger Flash, Steib S500.


Online Greybeard

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Re: Plunger Chaincase screws
« Reply #9 on: 03.03. 2019 19:54 »
... I stick with the original cheese-headed screws.
Fillister  *smile*

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Re: Plunger Chaincase screws
« Reply #10 on: 05.03. 2019 11:04 »
So some one who used cap heads would be a fillis-tine  Boom Tish.

The thing you have to be careful with when using cap is the head on them is about 1/2 the surface area of the correct Fillister heads.
So when done up a little too tight they mutilate the clamping face under the head and cause the alloy to collapse into the hole.
You should always use flat washers under allan headed caps to spread the load.
Allan headed caps were designed for use on machines that were steel not alloy so the head is the appropriate size for clamping down onto steel not alloy.
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Trevor

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Re: Plunger Chaincase screws
« Reply #11 on: 05.03. 2019 14:24 »
Fillister - that's the word! *smile*
2 twins, 2 singles, lots of sheep

Offline Russ

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Re: Plunger Chaincase screws
« Reply #12 on: 05.03. 2019 21:49 »
Diagram of Timing cover screws attached
1951 A10 Plunger.
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Offline a

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Re: Plunger Chaincase screws
« Reply #13 on: 06.03. 2019 03:31 »
Anyone looking for the "original Look" screw, we have them in 1 3/4" lengths for various applications. Sold in lots of 10

https://mikesclassiccyclespares.com/product/new-bsa-triumph-timing-primary-gearbox-cover-cheese-head-screws-1-4-unc/

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Re: Plunger Chaincase screws
« Reply #14 on: 06.03. 2019 08:51 »
Fillister